17 February 2015

Renowned Designer Explains Why All Typefaces Are Optical Illusions

When you look at a piece of typed text, it would seem that the capitals letters are all of a certain height, and that the lower case letters are also uniform in height.

Which is why you may be surprised to learn that all typefaces are optical illusions and that type designers are required to be “a bit of a magician” to do their work well—renowned designer and type historian Tobias Frere-Jones recently delved into this topic in a blog post.

While the letters may look to be of uniform height, the truth is that some of them are taller than others—this is because curved characters such as “C” and “O” are perceived to be shorter than squarish ones like “T” and “H”. This means that if all the letters are made to be of the same height, the sentences they make would actually be optically uneven.

Therefore, in order for the letters to look like they are of the same height, designers have to “cheat” by “overshooting” some of them—while this means that the letters are not mathematically uniform, Frere-Jones states that since “we read with our eyes, not with rulers, so the eye should win every time”.